/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.graby.store.portal.auth;

import java.io.Serializable;

import javax.annotation.PostConstruct;

import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.UsernamePasswordToken;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.ByteSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.utils.Encodes;

import com.google.common.base.Objects;
import com.graby.store.cache.Cache;
import com.graby.store.entity.User;
import com.graby.store.portal.service.AuthService;

public class ShiroDbRealm extends AuthorizingRealm {

	@Autowired
	private Cache<String,String> cache;
	
	@Autowired
	protected AuthService authService;

	/**
	 * 认证回调函数,登录时调用.
	 */
	@Override
	protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
		UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
		User user = authService.findUserByUsername(token.getUsername());
		if (user != null) {
			byte[] salt = Encodes.decodeHex(user.getSalt());
			String sessionKey = cache.get(user.getUsername());
			return new SimpleAuthenticationInfo(
					new ShiroUser(user.getId(), user.getUsername(), sessionKey, user.getShopName()), 
					user.getPassword(),	ByteSource.Util.bytes(salt), getName());
		} else {
			return null;
		}
	}

	/**
	 * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用.
	 */
	@Override
	protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
		ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
		User user = authService.findUserByUsername(shiroUser.username);
		SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
		info.addRoles(user.getRoleList());
		return info;
	}

	/**
	 * 设定Password校验的Hash算法与迭代次数.
	 */
	@PostConstruct
	public void initCredentialsMatcher() {
		HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(AuthService.HASH_ALGORITHM);
		matcher.setHashIterations(AuthService.HASH_INTERATIONS);

		setCredentialsMatcher(matcher);
	}

	@Autowired
	public void setAuthService(AuthService accountService) {
		this.authService = accountService;
	}

	/**
	 * 自定义Authentication对象，使得Subject除了携带用户的登录名外还可以携带更多信息.
	 */
	public static class ShiroUser implements Serializable {

		private static final long serialVersionUID = -1373760761780840081L;

		private Long userid;
		private String username;
		private String session;
		private String shopname;
		
		public ShiroUser(Long userid, String username, String session, String shopname) {
			this.userid = userid;
			this.username = username;
			this.session = session;
			this.shopname = shopname;
		}

		public String getUsername() {
			return username;
		}

		public Long getUserid() {
			return userid;
		}

		public String getSession() {
			return session;
		}

		public void setUsername(String username) {
			this.username = username;
		}

		/**
		 * 本函数输出将作为默认的<shiro:principal/>输出.
		 */
		@Override
		public String toString() {
			return username;
		}

		/**
		 * 重载hashCode,只计算loginName;
		 */
		@Override
		public int hashCode() {
			return Objects.hashCode(username);
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			ShiroUser other = (ShiroUser) obj;
			if (username == null) {
				if (other.username != null)
					return false;
			} else if (!username.equals(other.username))
				return false;
			return true;
		}

		public String getShopname() {
			return shopname;
		}
	}
}
